Seo Ju-hyun (born June 28, 1991), known professionally as Seohyun, is a South Korean actress and singer. She debuted as a member of girl group Girls' Generation (and later its subgroup TTS) in August 2007, who went on to be one of the best-selling artists in South Korea and one of South Korea's most popular girl groups worldwide. Apart from her group's activities, she has established herself as an actress, notably through her participation in the original and Korean versions of stage musicals including Moon Embracing the Sun, Gone with the Wind and Mamma Mia. She also starred in the drama Moon Lovers: Scarlet Heart Ryeo. She debuted as a solo artist with her debut mini album, Don't Say No, on January 17, 2017, making her the third Girls' Generation member to debut as a solo artist.